Hot bath tap problem - flow drops drastically

[jamiegleave]

Hi all

I was wondering if anyone can help me with an issue I have on my bath hot tap. I will try and be as detailed as I can.

I recently fitted a set of rather expensive Crosswater "Mike Lever" deck mixer taps to my bath, and since fitting about 8 months ago I have noticed the hot flow drops off after a couple of minutes filling the bath.

Now everywhere else in the bathroom, kitchen etc the hot flow rate is comparable to the cold when the taps are opened; both hot and cold fills a 1 litre jug in about 4 to 5 seconds so we have good pressure. The flow rate never changes and the heat is constant from all hot taps regardless of their location in the house.

The hot water system is ran of an Ariston e-combi 30 boiler, fitted less than 2 years old.

The hot bath tap flow is marginally less than elsewhere in the house, initially filling the jug in about 7 seconds. But after being on for a short time, the heat remains constant but the flow rate drops off massively. I timed this a few times today and the last attempt took some 25 - 30 seconds to fill the jug after being on for about 5 mins... It is proving impossible to fill a bath!

Does anyone have an idea what this could be? Is it the taps, the flexis or could it be a blockage in the hot water pipework to the mixer itself?

Any help appreciated.

Jamie

 

[Madrab]

Given the boiler can handle 12.9ltrs/min @ 35degC, it doesn't sound like that's the issue. Does this drop in flow happen with the other hot water outlets too or just the bath? If not, it may be an issue with the hot tap ceramic cartridge

 

[jamiegleave]

Just the bath tap drops in flow, others are all fine.

 

[kidgreen61]

I have come across this once, the prob was caused by a faulty flexi pipe.

What was happening, was that a flap of rubber in the flexi would (as it warmed up and became more pliable) move, and partially block the pipe.

Took me a while to find it!!